Conventionally, the outer lens portion of automobile lamp assemblies whether used on the rear, front or side surfaces thereof, have been divided into two or more distinct sections. At least one of these sections includes optical elements which transmit light from a light source in the assembly outwardly thereof, as is the case in the "taillight" sections or "brake light" sections, and another section made up of reflex elements the purpose of which is to reflect light from an exterior light source directed at the lamp assembly. As an example, optical elements of the lens are located outwardly of a light source in the body of the assembly. The optical elements, or optics as they are sometimes referred to, direct and transmit a first light source, for example a taillight bulb, and they also serve to direct and transmit the stronger light resulting from a brake application, or a directional signal in the case of a front or side located assembly, resulting from a higher intensity bulb being brought into play with a brake application or directional signal actuation. The reflex portion of the assembly consists of an arrangement of a plurality of multi-faceted elements that provide a reflective brilliance to a light source directed at the assembly from the exterior thereof, for example, from the head lights of another automobile being directed at a rear lamp assembly incorporating the reflex elements in question. The brilliance of the reflective elements must meet standards set by various countries.
Examples of the prior art may be found in German Offenlegungsschrift 2 230 584, 28 Dec. 1972,
U.S. Pat. No. 3,632,695 of Jan. 4, 1972; and
U.S. Pat. No. 4,198,182 of Apr. 15, 1980.
DE-A-2 230 584 illustrates a plane of optical elements parallel with a plane of reflex elements.
U.S. Pat. No. 3,632,695 discloses a method of making a combined lens and reflector in which a plurality of pins having shaped ends are assembled in a bundle and replacing portions of the shaped ends where optical elements are to be formed. A mold is electroformed over the shaped ends and subsequently the electroform mold is shaped at the areas of the optical elements to form the desired optical surfaces.
U.S. Pat. No. 4,198,182, there is disclosed a lamp lens mold in which the mold plate has a plurality of recesses in one face thereof and in which each of the recesses is adapted to produce a projection on one face of the lens element and is shaped so as to define in the projection a lens integral with and overlying a prism.
Automotive lamp assemblies and their lenses are relatively simple to manufacture when the areas of the vehicles on which they are mounted are relatively flat. However, with the evolution of automobile bodies that are more smoothly contoured both on rear surfaces as well as the front surfaces thereof to reduce the coefficient of drag, it has become more difficult to manufacture suitable lenses that will blend into these contours and which will still provide the desired degrees of reflective and optically transmitted brilliance of stop lights, taillights, directional signal lights and fog lights.
There is also a need for a single, unitary lens which will meet the needs for application to automotive vehicles that have smoother, rounded styling and yet which can be tailored to the specific functions of the lamp assembly for a particular vehicle. For example, lamp assemblies on automobiles must function with regard to the front and rear portions of the vehicle and, to meet safety requirements of certain countries, the lamp assemblies must have lenses that extend into portions of the side surfaces of the vehicle. There is often compound curvatures to the surfaces that the lenses must match.
Design requirements for the newer generation of automobiles also dictate preferences that the reflective areas of the lamp assemblies be integrated with the tail and stop light areas of the assembly and the fog light areas of European assemblies.
The requirements for the new contoured lamp assemblies and lenses provide challenges for the manufacturer of the lenses as well. Conventionally, the lenses have optical elements as well as reflex elements and were manufactured by assembling a large plurality of reflex pins into a packet or bundle thereof, if necessary forming a mold by electro-depositing metal on the shaped ends of the reflex pins and then using the resulting electro-form to inject a plastic material thereon to form the reflected surfaces.
The reflex portions of the lens would be used in combination with optical elements resulting from the optics being machined on to a metal block which was added to the bundled reflex pins or an electro-form therefrom. The unitary piece of plastic material manufactured from the block-machined optics and the bundled reflex pins provided a combined lens and reflector whereby the unit could both transmit and direct light from a light assembly source and to reflect light from for example another vehicle.
By integrating reflex elements into light assemblies which follow the contour of the body of a vehicle, the pins, as well as optics, are positioned in the blocks so that the rearward reflection or the transmitted direction of the finished optics takes place in a direction which is parallel to the longitudinal axis of the vehicle or as close to that as possible.